Vacuum cleaner suction device



May 8, 1956 N. E. AHLSWEDE 2,744,678

VACUUM CLEANER SUCTION DEVICE Filed May 20, 1952 2 Sheets-Sheet; 1

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May 8, 1956 N. E. AHLSWEDE VACUUM CLEANER SUCTION DEVICE 2,Sheuts-She'bt 2 Filed May 20, 1952 nuemmmb United States Patent VACUUMCLEANER SUCTION DEVICE Norman E. Ahlswede, Morton Grove, Ill., assignorto Birtman Electric Company, a corporation of Illinois Application May20, 1952, Serial No. 288,884

6 Claims. (Cl. 230117) This invention relates to a vacuum cleaner andparticularly to a motor driven suction device for use therein.

In vacuum cleaners and similar machines the suction is ordinarilycreated by means of a motor driven fan unit. Where a relatively highsuction is to be developed in the cleaner, the unit preferably employs aplurality of fan stages. Such a construction is quite simple to build intank type cleaners as here ample space is usually available for theplurality of stages. However, in the rotary brush type cleaner that isadapted to be propelled over the floor by means of a handle, space isquite limited so that the fan has ordinarily been a single stage vacuumfan. This is true because the propelled rotary brush cleaner can beneither too long where the motor-fan unit is horizontal nor too highwhere the motor-fan unit is arranged vertically.

The vacuum cleaner of this invention employs a multi stage fan and motorunit constructed in such a way that the high vacuum of such a fan isobtained Without the usual excessive length so that the unit will easilyfit into the available space in a motor brush type cleaner.

The invention will be described-as related to the embodiment shown inthe accompanying drawings. Of the drawings: Figure l is a side elevationof a vacuum cleaner embodying the invention with this elevation beingpartially in section; and Figure 2 is a plan view of the vacuum cleanerof Figure 1.

In the vacuum cleaner shown in the accompanying drawings there isprovided a body 10 supported on spaced wheels 11 and 12 and formed atthe front end thereof with a suction nozzle 13. Within the body 10 atthe front thereof there is provided a chamber 10a adapted to contain adust intercepting filter unit 14 into which dust laden air is adapted toflow from the nozzle 13. Immediately beneath this chamber 10a is anelongated chamber 10b extending toward the rear of the cleaner andadapted to contain a belt 15 for driving a rotary brush 16.

In order to create a relatively high suction in the vacuum cleaner therear portion thereof is provided with a suction unit including a motor17 and a multi-stage fan 18. The motor includes a rotor 19 mounted forrotation with a motor shaft 20 and surrounded by the usual fieldlaminations 21 and field coils 22. Extending through the top of thecleaner body 10 is an ordinary electric cord 23 for supplyingelectricity to the motor 17. Also attached to the cleaner body at therear thereof is an ordinary handle for propelling the cleaner andincluding a pair of bail portions 24 and 25.

The motor shaft 20 is arranged essentially vertically and is supportedby top and bottom bearings 26 and 27. The top bearing is supported in anannular flange 28 on the top wall of the cleaner body while the bottombearing 27 is supported by an annular flange 29 formed as a part of apartition wall 30. This partition wall 30 is provided with an air inletopening 30a through which air is drawn by the fan 18 from the nozzle 13,through the filter unit 14, up through the fan 18, around the motor 17,and out an exit opening 100 at the rear of the cleaner body.

In order to make the suction unit as short as possible and thus avoidexcessive height in the cleaner at the rear thereof, a commutator 31 forthe motor is positioned between the upper stage 32 and the lower stage33 of the fan. With this arrangement the upper stage 32 can be locatedclosely adjacent to the rotor 19 and the commutator 31 thus occupiesspace that is normally wasted in the ordinary multi-stage fan and motorcombination. In the embodiment shown the upper stage 32 of the fan islocated adjacent to a transverse baflie 34 provided with an air inletopening 34a for air flowing between the two stages of the fan.

In order to further save space and reduce the overall length of the unitthe lower bearing 27 is preferably located within the entrance to thelower fan stage 33. Thus here again the bearing is positioned within aspace that is ordinarily wasted in the usual multi-stage fan.

As can be seen in Figure l, the commutator 31 is of the usual relativelylarge diameter. Similarly the portion 35 of the motor between thecommutator and the rotor 19 is also of large diameter and the portionbetween the bearing 27 and the commutator 31 is only slightly smallerthan the diameter of the commutator. With this arrangement each fanstage can be made of relatively light weight materials. Thus the upperfan stage 32 is constructed of relatively thin parallel sheet metal sideportions 36 and 37 having a plurality of fan blades 38 therebetween. Theside portion 36 is attached to a relatively heavy plate 39 ofconsiderably less diameter than that of the portion 36 in order to giverigidity to the structure. The lower fan stage 33 is similarlyconstructed and attached to a similar circular plate 40 at the lower endof the commutator 31. The bottom end of the shaft 20 extends beyond thelower bearing 27 and is shaped to provide a drive spindle 41 for thebelt 15, with this spindle also being located with the belt in thebottom chamber 10b.

When the motor driven fan unit is being operated air is drawn in throughthe inlet opening 30a in the wall 30 and is forced out between theblades in the lower fan stage 33 to the periphery thereof. From thisperiphery the air is directed by the baflle 34 into the baflle opening34a and then out between the fan blades 38 at the upper fan stage 32.From here the air flows around the motor 17 and out the exit 100. Withthis construction the commutator 31 which is located almost entirelywith the chamber 10d defined by the wall 30 and battle 34 has airdirected across it in order that maximum cooling is achieved.Furthermore, space is further conserved by locating the upper end of thecommutator 31 within the air inlet opening 34a of the baflle 34.

As is shown in Figure 2 the two brushes 42 for the motor are alignedtransversely of the cleaner with each brush being held in asubstantially cylindrical housing 43. The brushes are also positioned inthe air stream so that maximum cooling is achieved and they are solocated as to use space that was formerly wasted.

The baffle 34, the two transverse air straightener baffles attached tothe bottom thereof as shown in Figure l, and the brush holders 43 may bein the form of a single unit insertable into and removable from the rearportion of the cleaner body 10.

Among the advantages of the structure shown and described herein is theconservation of length in the motor and fan unit so that a multi-stagefan can be used in a vertically arranged unit without drasticallyincreasing the height of the cleaner. This is achieved by locating thevarious parts of the unit in space that was formerly Wasted. Anotherimportant advantage is that improved cooling of the commutator, brushes,bearings, and other parts of the motor is achieved by locating theseparts within or closely adjacent to the suction air stream.

Although the invention has been described as embodied in a vacuumcleaner, it is believed obvious that the same principles can be used inany motor driven suction device using a combination of a motor and amulti-stage fan where the length of the device is maintained at aminimum.

The foregoing detailed description is given for clearness ofunderstanding only, and no unnecessary limitations should be understoodtherefrom as modifications will be obvious to those skilled in the art.

I claim:

1. In a vacuum cleaner, an essentially vertical suction unit ofrelatively short length to reduce the overall height of the cleanercomprising a motor including a shaft and a rotor mounted thereon, amulti-stage fan on the shaft on one side of the motor, a commutator onthe shaft between two adjacent fan stages, and a shaft bearingpositioned within the inlet of the outermost fan stage.

2. In a vacuum cleaner, an essentially vertical suction unit ofrelatively short length to reduce the overall height of the cleanercomprising a motor including a shaft and a rotor mounted thereon, amulti-stage fan on the shaft on one side of the motor, and a commutatoron the shaft between two adjacent fan stages and in contact with the airstream flowing therebetween.

3. In a suction device of relatively short length, a motor including ashaft and a rotor mounted thereon, a pair of spaced shaft bearingsengaging the shaft on opposite sides of the rotor, a two-stage fan onthe shaft between one end of the rotor and a bearing with each stagehaving a centrally located air inlet, and a commutator on the shaftbetween the fan stages, one of the bearings being located within theinlet of the outermost fan stage.

4. In a suction device of relatively short length, a motor including arotor, a multi-stage fan on one side of the rotor and rotated therebywith each stage having a centrally located air inlet, a commutator onthe shaft located between two adjacent fan stages, and a bearing for therotor engaging the shaft and positioned within the inlet of theoutermost fan stage.

5. The suction device of claim 4 wherein a pair of commutator brushesare provided between said two fan stages for contact with the airflowing therebetween.

6. In a suction device of relatively short length, a motor including arotor, a multi-stage fan on one side of the rotor and rotated therebywith each stage having a centrally located air inlet, and a commutatoron the shaft located between two adjacent fan stages of said multi-stagefan.

References Cited in the file of this patent UNITED STATES PATENTS1,572,269 Cramer Feb. 9, 1926 1,718,804 White June 25, 1929 2,064,587Carlstedt Dec. 15, 1936 2,121,073 De Bothegat June 21, 1938 2,224,202Smellie Dec. 10, 1940 2,228,750 Brock Jan. 14, 1941 2,257,555 TroxlerSept. 30, 1941 2,297,283 Berg Sept. 29, 1942 2,604,501 Wightman July 22,1952 2,658,665 Tschudy Mar. 10, 1953

